Olivia has taken an initial dose of a prescription
 medication.
 The relationship between the elapsed time t, in hours,
 since she took the first dose, and the amount of
 medication M(t), in milligrams (mg), remaining in her
 bloodstream is modeled by the following function.
 M(t) = 50 .e-0.75t
 How many milligrams of the medication will be remaining
 in Olivia's bloodstream after 6 hours?
 Round your answer, if necessary, to the nearest 
 Hundredth